Δ2-1,2,4-Oxadiazoline durch Kondensation von Amidoximen mit Ketonen und Aldehyden

Δ²-1,2,4-Oxadiazolines by Condensation of Amidoximes with Ketones and Aldehydes Using acetic acid as a solvent, ketones and aromatic aldehydes react with amidoximes 1 to cyclic products, Δ²-1,2,4-oxadiazolines 3 . The lack of reactivity in neutral milieu is explained by MNDO calculations. Protonated carbonyl compounds are discussed to be the reactive species.     

Umsetzung von 1,2-Dihydro-3-indazolon mit ω-Dialkylaminoalkylhalogeniden und α,ω-Dihalogenalkanen

Reaction of 1,2-Dihydro-3-indazolone with ω-Dialkylaminoalkyl Halides and α, ω-Dihalogenalkanes The reaction of the potassium salt of 1,2-dihydro-3-indazolone with ω-dialkylaminoalkyl halides in anhydrous dioxane leads to basic lactim ethers, which are analgesics. On the other hand two basic compounds are formed, when α, ω-dihalogenopropanes participiate. Compound 1 was identified as 3,4-dihydro-2H-[1,3]oxazino[2, 3-b]indazole and compound 2 as 2,3-dihydro-lH-pyrazolo[1,2-a]indazol-9-one. Compound 2 is reduced by LiAlH₄, to 2,3-dihydro-lH, 9H-pyrazolo[1, 2-a]indazole ( 5 ).     

2-Azetidinone: Die Reaktion von α-Silylcarbanionen mit Mesoxalsäurediethylester

2-Azetidinones: The Reaction of Diethyl Ketomalonate with α-Silylcarbanions 1,4-Diaryl-2-azetidinones 1 are base-catalysed silylated at ?78°C, forming 2 . The title reaction, starting with the anion of 2 , results in the formation of the dimeric products 4 . The structure of 4 is elucidated by X-ray analysis. In the presence of chlorotrimethylsilane, the α-silylcarbanion of 2 reacts with diethyl ketomalonate 3 to form 3-methylene-2-azetidinones 8 resp. 11 .     

Darstellung von γ- und δ-Laktoncarbonsäuren aus DL-3-(1′-Methoxymethylpropyl)-glutarsäure

Ether cleavage of DL -3-(1′-methyoxymethylpropyl)-glutaric acid with the protonic acid HBr leads to 4-carboxymethyl-5-methyl-5-ethyl-furanone-(2);ether cleavage with the Lewis acid BBr₃ to carboxymethyl-5-ethyl-pyranone-(2).     

Diindolylmethane, 4. Mitt. Säure-katalysierte Kondensation von 3-Methylindol und Tryptophanmethylester mit sterisch anspruchsvollen aromatischen Aldehyden

Diindolylmethanes, IV: Acid Catalyzed Condensation of 3-Methylindole and Methyl Tryptophanate with Sterically Hindered Aromatic Aldehydes The 3-substituted indoles 1 and 2 react with 2,6-dimethoxybenzaldehyde ( 3a ) to yield the diindolylmethanes 4 and 6 by acid catalysis. The reaction of 2 with 3a also yields the tetrahydro-β-carboline 7 . The sterically hindered mesitylaldehyde ( 3b ) reacts only with the indole 1 to give the 2,2′-diindolylmethane 5 , while the tryptophane methyl ester 2 yields the tetrahydro-B-carboline 8 only.     

Phosphorsäureester von Adamantanolen, -thiolen,Adamantylalkoholen und Derivaten, 1. Mitt. Synthese der Phosphorsäureester durch Reaktion mit 2-Chlor-1,3-dioxa-2-phosphorindan-2-oxid

Phosphoric Esters of Adamantanols, Adamantanethiols, Adamantyl Alcohols and Their Alkyl Derivatives, I: Synthese of the Phosphoric Esters by Reaction with 2-Chloro-1,3-dioxa-2-phosphorindane-2-oxide Numerous adamantanols, adamantanethiols, adamantyl alcohols and derivatives thereof were converted into phosphoric esters. 2-Chloro-1,3-dioxa-2-phosphorindane-2-oxide proved to be a suitable phosphorylating agent, which reacted completely and rapidly with most of the tertiary and sterically hindered alcohols and thiols. The structures of the by-products were elucidated. The influence of various parameters on the course of the reaction is described.     

2-Azetidinone: Die Reaktion von α-Silylcarbanionen mit Carbonylverbindungen

2-Azetidinones: Reaction of α-Silylcarbanions with Carbonyl compounds Azetidinones 1 are deprotonated by LDA and reacted with various carbonyl compounds yielding substituted 3-methylene-2-azetidinones 3 – 5 . As a byproduct in these reactions, the vinylsilane 6 was isolated. 6 may be synthesized directly from 1 in good yield.     

Phosphorsäureester von Adamantanolen, - thiolen,Adamantylalkoholen und Derivaten, 3. Mitt. Oberflächenaktivität und bakteriologische Untersuchungen

Phosphoric Esters of Adamantanols, Adamantanethiols, Adamantyl Alcohols and Their Alkyl Derivatives, III: Surface Activity and Bacteriological Tests Data are presented on the surface activity and on bacteriological tests of triethylammonium salts of o-hydroxyphenyl phosphate esters of adamantanols, adamantanethiols, adamantyl alcohols and their alkyl derivatives. Strong correlations between chemical structure and surface activity were found in homologous series of highly tensioactive ester salts. Lipid-water partition and surface activity could also be correlated. Bacteriological tests did not prove antibacterial activity of the ester salts.     

Massenspektrometrische Untersuchungen an isomeren α,β- und β, γ-ungesättigten Ketonen mit raumerfüllenden Substituenten

A Mass Spectrometric Study on Isomeric α,β- and β,γ-Unsaturated Ketones with Bulky Substituents The mass spectra of the α,β- and β,γ-unsaturated ketones 1-4 (scheme 1) are very different depending on the stereochemistry of the double bond. The E-configurated ketone 2 predominantly shows McLafferty fragmentation, whereas Z-configurated ketone 1 reveals ?-cleavage. In the β, γ-unsaturated ketones 3 and 4, mainly loss of the pertinent allyl radical by α-cleavage was observed.     

Die Synthese von β-Phenyl-isoserinen durch Ammonolyse von β-Phenylglycidestern,II

Synthesis of β-Phenyl-isoserines by Ammonolysis of β-Phenylglycidates, II Ammonolysis of the β-phenylglycidates 1a–e yields the erythro-isoserine-amides 2a–e , from which the acids 3a–e can be obtained by hydrolysis. 1a with benzylamine also gives the isoserine derivative 8 . On the other hand, treatment of 1a with piperidine affords the serine-compound 6 . The structures are confirmed by the NMR-spectra and by comparison with the corresponding serines 4a–e .     

Untersuchungen an β-Sultonen, 3. Mitt. Zur Darstellbarkeit von 1,2-Oxathietan-2,2-dioxiden (β-Sultonen) und deren Reaktionen mit Nucleophilen

β-Sultones, III: The Preparation of 1,2-Oxathietane 2,2-Dioxides (β-Sultones) and Their Reactions with Nucleophiles Some new compounds were added to the as yet small group of β-sultones with hydrogen attached to the ring system. Reactions of these β-sultones with nucleophiles yielding β-hydroxyethanesulfonyl derivatives were investigated.     

Zur Umsetzung von Aceton-1,3-dicarbonsäure-dialkylestern und 1,3-Diacetyl-aceton mit Stickstoffoxiden

The Reaction of Dialkyl Acetone-1,3-dicarboxylates and 1,3-Diacetylacetone with Nitrogen Oxides Dialkyl acetone-1,3-dicarboxylates 4a - d react with dinitrogen trioxide/nitric acid to give the crystalline 3,5-dialkoxycarbonyl-4-oxo-4H-pyrazole 1,2-dioxides 5a - d and the oily dialkoxycarbonylfuroxanes 6a - d . Compounds 4e - f react to yield 6e - f only. From 1,3-diacetylacetone ( 7 ) the symmetric 3,5-diacetyl-4-oxo-4H-pyprazole 1,2-dioxide ( 8 ) is formed.     

Thion- und Dithioester, 38. Mitt. Zur Kondensation von 2-Amino-dithiooxalsäure-O-ester mit Cyanessigestern

Thiono- and Dithioesters, XXXVIII: Condensation of 2-Amino-dithio-O-oxalates with Cyanoacetic Esters By thiolysis of the cyano methanimidoates 2 cyano methanethioates 1 or 2-amino-2-thioxoethanethioates 3 are formed, depending on the reaction conditions. The thionoester group in 3 condenses with cyanoacetates in the presence of potassium methoxide to form the potassium salts 7 , which were S-alkylated to give the thioenol ethers 9 . Condensations of 9 with hydrazines lead to structurally different products 11–18 .     

Kondensationen mit Hydrazin-N,N′-dicarbonsäurediamidin, 21. Mitt. β-Ketocarbonsäureester als Reaktionspartner

Condensations with 1,2-Hydrazinedicarboxamidine, XXI: β-Ketocarboxylic Esters as Reactants In preceding investigations it was assumed that the guanidinoaminopyrimidine structure is a common intermediate in the formation of hydrazo- and the triazolopyrimidines from 1,2-hydrazinedicarboxamidine (1) . This postulate is now supported by the isolation of 2-guanidinoamino-6-methyl-1,4-dihydropyrimidin-4-one (3) formed by the reaction of 1 with ethyl acetoacetate (2) and by the conversion of 3 into 2-amino-7-methyl-5,8-dihydro-s-triazolo[1,5-a]pyrimidin-5-one (8a) . In the course of this conversion 6,6′-dimethyl-2,2′hydrazo-1,4-dihydropyrimidin-4-one (4) is formed from 3 .     

Darstellung und Reaktivität von α-Acyloxy-N-acylglycin-Derivaten

Synthesis and Reactivity of Derivatives of α-Acyloxy-N-acylglycine The N,O-Acylals 5–15 are obtainable from the chloro compounds 2 and carboxylic acids. Treatment of the electrophilic synthons with nucleophiles under basic conditions leads to products 16–19 by way of transamidoalkylation. A mechanism of the reaction is proposed.     

Heterocyclisierungen an Ascorbinsäuren mit α, ß- ungesättigten Aldehyden und Ketonen, 2.Mitt.: Michael-Reaktionen von Ascorbinsäuren mit Acroleinderivatenstrukturelle und physikochemische Beobachtungen

Heterocyclisations of Ascorbic Acids with α, β-Unsaturated Aldehydes and Ketones, II: Michael Reactions of Ascorbic Acids with Acrolein Derivatives - Structural and Physicochemical Behaviour. The Michael reaction of ascorbic acids ( la – d ) with acrolein ( 2 ) and some derivatives ( 7 , 8 ) is reported. The pH-optimum of the reaction course is 4. Furthermore, solvents supporting ionisation are favourable. α- and β-subsituted acrolein derivatives react differently: Crotonaldehyde, a β-substituted derivative, reacts nearly quantitatively to the spiro compounds 3e and 3f , whereas α-ethyl-acrolein favours the formation of 4g and 4h .